I, too, take notes and make rough drawings - just not in a journal. Instead I use whatever scrap of paper lying nearby when an idea pops up. (and sometimes they get lost, go figure)
When I get my craft room ( in a couple of weeks), the first thing I'll be making is a journal - such a great idea, same as the cover for the PM.
Oh, a craft room - with everything at arms reach, everything ready, a wall to wall tabletop, table to ceiling shelves and drawers - NOW, THAT'LL BE CLAY HEAVEN!! And definitely improve my work and lengthen my clay time.